This invention relates to a method of purifying water to so as be suitable as drinking water a with high density light beam obtained by condensing solar light and the apparatus used for the same method.
Water in rivers, lakes and ponds is converted to drinking water by various methods such as a water purification plant system, a reverse osmosis system, an electrodialysis system, a freezing system, a distillation system (of a heating type or a pressure reduction type) and a boiling system.
The water purification plant system produces drinking water through precipitation in sand, followed by filtration and chlorine sterilization. This system requires a large amount of land and a high output water supply pump. In addition, the chlorine-based chemical which is introduced for the purpose of sterilization is liable to pose a problem of physical troubles due to the remaining chlorine component.
The reverse osmosis method is mainly utilized for converting sea water to fresh water. In this system, sea water is passed through an osmosis film with application of current to obtain fresh water. This system, however, requires a large-scale pressure application pump power as well as maintenance and renewal of the osmosis film.
The freezing system produces drinking water by overcooling water, separation by atomizing and then thermal dissolution. Again this system, however, requires great power. In addition, great cooling energy is necessary.
In the distillation system, water is evaporated by heating and then condensed by cooling to obtain drinking water. In the boiling system, material water is primarily filtered, then boiled and then secondarily filtered to obtain drinking water This system is simple compared to the systems noted above. However, for sterilization as a main step an conversion of water to drinking water, heating and temperature elevation of water which require heat of evaporation and great heat, are involved. Therefore, the heat energy consumption is increased, that is, the amount of final water produced is reduced with the same heat energy consumption.
Meanwhile, in the case of the supply of drinking water in tropical and subtropical regions, harmful bacteria and micro-organisms readily propagate in original water to be processed, and perpetual and strong caution of peccant bacteria causing endemic diseases is indispensable. There are fixed corruption and bacteria growth allowances for the quality of original water suited for the production of drinking water. Generally, it is not easy both technically and economically to convert water in rivers and lakes to drinking water, and there is no convenient and theoretically inexpensive means effective against high concentration bacteria and viruses as described above in connection with the prior art.